CPW drafts CWD response plan

RBC | Last month Colorado Parks and Wildlife (CPW) held meetings in Meeker and Craig explaining their increasing concern relative to the presence of Chronic Wasting Disease (CWD) in the area mule deer herd. In some upriver Game Management Units, the prevalence rate as shown by tissue sampling via hunter harvest, primarily, has grown to nearly 27 percent. By contrast, the Piceance Creek GMU #22 herd shows only about a 2 percent prevalence rate.

With the help of a CWD Advisory Group, CPW is drafting a statewide CWD Response Plan. CPW personnel, the advisory group and members of the interested public met again in Rifle on July 25 and  reviewed their draft plan. Craig outfitter and wildlife control professional Chris Jurney is a member of the group. He said his role is advisory only and that CPW personnel who are drafting the plan.

“The group was given a lot of information to review, discuss and critique… in addition, we came up with some different ideas, suggestions and additional scientific studies,” Jurney said, adding “some of the group and many outside [public] individuals remain extremely critical of the plan, including the 10 and 5 percent prevalence thresholds” for management actions discussed below. Jurney says there is skepticism about [increased] removal of uninfected mature bucks in order to try to slow the spread of CWD.”

Further review and the approval process of the draft plan will take place this fall. The final draft is to be presented to the CPW Commission at its November meeting in Burlington, Colo., with approval, or not, to occur at the December meeting (location to be announced). The Advisory Group is expected to have more public meetings around the state.

CPW has seen a significant decline in CWD prevalence in the Red Feather Lakes/Poudre Canyon deer herd where they’ve applied focused culling and increased harvest in recent years. Similarly, the prevalence rate has dropped in the Middle Park herd where relatively aggressive buck and doe harvests have been implemented during the last decade.

The draft plan is designed to take a long-term (at least 15 year) management approach that will test the efficacy of different actions taken to attempt to control the higher CWD rates. Hunter harvest (licensing) will continue to be the primary tool for implementing herd specific actions by GMU. Such specific actions are to be determined by local herd managers in concert with the herd management plans.

The core objectives of the Plan are to 1) reduce or maintain CWD prevalence in free-ranging deer herds below the management threshold set by the plan. Prescribed management actions will intend to maximize control of CWD prevalence while minimizing the impact of both the disease and its management on herds; 2) provide the public with science-based information regarding CWD; 3) maintain Colorado’s robust deer herds to support public hunting and viewing opportunity; and 4) provide guidance for 15 years of CWD surveillance, monitoring and management in Colorado’s deer herds and a framework to test how prevalence rates respond to prescribed management actions.

Increased surveillance and monitoring—Sampling will focus on higher risk individual animals: those that are symptomatic or are killed by vehicles, predators or hard winter conditions. Symptomatic individuals will be culled and tested by CPW personnel. So far in Colorado, 24 (of 55) deer herds, 27 (of 43) elk herds, and seven (of nine) moose herds appear to be CWD-free.

The plan sets forth a schedule of six to eight deer herds each year in which hunters will be subject to mandatory presentation of harvested heads for testing. The next year, six to eight different herds will have mandatory testing, and so on, so that all the heard units will be surveyed over about five years when the rotation repeats. The plan will be under regular reassessment and adaptive management.

CPW may also consider incentivizing voluntary testing outside the mandatory-targeted herds each year by offering free CWD testing. The cost for implementing the plan—which is about 90 percent in temporary personnel and the testing—is estimated at $175,000 to $200,000 annually, or $2.6 to $3 million for the 15 years.

Compulsory Disease Management—The draft plan suggests a threshold prevalence rate of 5 percent in a herd as the point at which management meant to reduce that rate will be required. At less than 5 percent in a given herd, only those actions deemed important for keeping the rate below 5 percent are suggested. Again, prescribed management actions for each herd, or herd subset, are to be decided by local managers in concert with the already approved herd management plan which use the best scientific information available in the context of habitat characteristics and social (human and environmental) carrying capacity. The draft plan will be implemented in the context of added emphasis on deer herd (Data Analysis Unit) management plans.

In agreement with the Western Association of Fish and Wildlife Agencies recommendations for adaptive management of CWD, the Plan leans on three principles: reducing artificial points of herd concentration; hunter harvest management; and harvesting targeted disease foci, using before-after-control-impact design evaluation of treatments. Incorporated into the adaptive planning is maximum flexibility to customize treatments and always be open to new ideas.

  Treatment Options Considered for Use Include—  Reduced population or density focused on specific herd area, aimed at the lower end of HMP population objectives but remaining within those approved numbers. If the prevalence rate is greater than 10 percent in a herd area, then more aggressive treatments are to be used between the first and second mandatory testing years for that herd.

Reduced Male:Female Ratio —This treatment option reflects that adult male deer (bucks) have double the infection rate of equivalent age does. Tactics to be used here and if population reduction is a goal are increased number of buck licenses, increasing or shifting buck harvest into later seasons, adjusting hunt codes to better target specific subset of herd, eliminate floating license numbers to  better control pressure, and increase opportunities for harvest by changing buck licenses from A to B List licenses, increasing private land only licenses, and establishing more special hunts.

Changing Herd Age Structure —Increase harvest of most likely infected four to six year old bucks while increasing the number of one to three year old bucks, and implement antler point restrictions. Tactics used otherwise essentially the same as above.

Maximize Ability to Remove Diseased Animals at the Smallest [Landscape] Scale Possible, i.e., hit hot spots—CPW can identify hot spots via their harvest data.

Remove Motivations that Cause Animals to Concentrate—Better control over any intentional or accidental feeding areas, salt blocks, harvested crop areas, etc.

Minimize Prion Point Sources—Better control handling of carcass parts by hunters, outfitters, taxidermists, and meat processors, with special treatment in landfills.

Incorporate CWD Management Actions and Prevalence Thresholds in Herd Management Plans.

Monitor, Reassess and Adapt Plan Going Forward—Produce annual evaluation report to CPW Commission; continue concerted, sustained effort (Response Plan) for at least 15 years.

As for elk and moose, no threshold for compulsory intervention has been determined at this time. Prevalence rates in elk and moose are significantly enough lower than in deer that CPW will focus CWD management efforts on deer and concurrently monitor prevalence trends for all three species through testing of voluntary submissions. Should the prevalence rates for elk or moose sharply increase, CPW will consider setting an appropriate statewide CWD prevalence threshold for each species.

Regional members of the CWD Advisory Group, in addition to Jurney, include Troy Sweet, Rocky Mountain Elk Foundation, Grand Junction; Don Cook, Moffat County Commissioner, Craig; and Marie Haskett, Meeker outfitter and a member of the Parks and Wildlife Commission. The plan can be tracked on the CPW website at the CWD page and contacted at DNR_AskCWDAdvisoryGroup@state.co.us.


By Reed Kelley | reed@theheraldtimes.com